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Tivers MS Travis TR Windsor RV Hotston Moore A 《The Journal of small animal practice》2005,46(9):430-435
OBJECTIVES: To gather information about the different techniques employed in general practice and to compare this with current undergraduate teaching. This would provide an insight into any areas of discrepancy and influences on technique in practice. METHODS: A questionnaire was composed and distributed to 407 practices throughout the UK, using a commercial mailing list. Fifty further questionnaires were distributed by final-year students to their foster practices and five were sent to practices on request. A second questionnaire was composed and sent to the members of staff responsible for teaching surgical neutering techniques at each of the UK veterinary schools. RESULTS: Completed questionnaires were received from 183 respondents. These were compared with seven questionnaires from university teachers. Only areas in which the teachers reached a consensus of opinion were directly compared. CLINICAL SIGNIFICANCE: Several areas of discrepancy between current teaching and techniques in practice were identified. A study of complications compared with technique would provide further information. There is a lack of published material or an evidence base in many aspects of surgical neutering to support one technique over another. 相似文献
115.
D. Layne Coppock Donald L. Snyder Louise D. Sainsbury Mansi Amin Travis D. McNiven 《Strength and Conditioning Journal》2009,62(3):253-267
It is hypothesized that Utah beef producers in certain locations could intensify private land use via improved forages and irrigation. Although intensification could increase ranch productivity and help compensate for any future restrictions in public grazing, is the approach profitable and sustainable in a dynamic environment? We investigated the efficacy of intensification using linear programming for three size-classes of model ranches. Model solutions maximize returns net of forage costs; outputs include brood-herd dynamics, optimal forage mixes, and net returns. The model is driven by 11-year risk scenarios combining high or low precipitation with high or low beef prices. We then consider current or no access to public grazing—a policy uncertainty. In general, results support the idea that intensification could be profitable, sustainable, and strategically useful under several sets of conditions. Modeled brood-herds expand and contract in response to precipitation. Optimal forage use is dominated by reliance on treated, improved, and irrigated forages. Critical irrigated forages include alfalfa hay and improved pasture. Profitability generally increases with operation size, but when public grazing is eliminated, herd sizes and profitability drop. Small and medium-sized operations respond to loss of public grazing by using more irrigated pasture and alfalfa hay, while larger operations use a wider variety of irrigated and nonirrigated forages. Sensitivity analysis indicates that optimal forage mixes for all operations remain stable even when input costs for fossil fuels double. Further increases in fuel costs, however, begin to reduce the contributions from irrigated pasture and alfalfa hay. Low precipitation (drought) has very large and negative effects on profitability in general. When drought combines with restricted access to public grazing, profitability of small and medium-sized operations drops further while profitability of large operations increases. Empirical research is needed to test model results and examine what the limiting assumptions reveal about real-world production constraints. 相似文献
116.
Carter JA Agol E Chaplin WJ Basu S Bedding TR Buchhave LA Christensen-Dalsgaard J Deck KM Elsworth Y Fabrycky DC Ford EB Fortney JJ Hale SJ Handberg R Hekker S Holman MJ Huber D Karoff C Kawaler SD Kjeldsen H Lissauer JJ Lopez ED Lund MN Lundkvist M Metcalfe TS Miglio A Rogers LA Stello D Borucki WJ Bryson S Christiansen JL Cochran WD Geary JC Gilliland RL Haas MR Hall J Howard AW Jenkins JM Klaus T Koch DG Latham DW MacQueen PJ Sasselov D Steffen JH Twicken JD Winn JN 《Science (New York, N.Y.)》2012,337(6094):556-559
In the solar system, the planets' compositions vary with orbital distance, with rocky planets in close orbits and lower-density gas giants in wider orbits. The detection of close-in giant planets around other stars was the first clue that this pattern is not universal and that planets' orbits can change substantially after their formation. Here, we report another violation of the orbit-composition pattern: two planets orbiting the same star with orbital distances differing by only 10% and densities differing by a factor of 8. One planet is likely a rocky "super-Earth," whereas the other is more akin to Neptune. These planets are 20 times more closely spaced and have a larger density contrast than any adjacent pair of planets in the solar system. 相似文献
117.
Gregory P Lardy Travis D Maddock 《Veterinary Clinics of North America: Food Animal Practice》2007,23(1):21-28
Creep feeding can be used to increase calf weaning weights. However, the gain efficiency of free-choice, energy-based creep feeds is relatively poor. Generally, limit-feeding, high-protein creep feeds are more efficient, and gains may be similar to those produced by creep feeds offered free choice. Creep feeding can increase total organic matter intake and improve the overall energy status of the animal. Creep-fed calves tend to acclimate to the feedlot more smoothly than unsupplemented calves. Furthermore, provision of a high-starch creep feed may have a positive influence on subsequent carcass quality traits. Creep feeding can be applied to numerous environmental situations to maximize calf performance; however, beef cattle producers should consider their individual situations carefully before making the decision to creep feed. 相似文献
118.
Forest productivity and tree diversity relationships depend on ecological context within mid-Atlantic and Appalachian forests (USA) 总被引:1,自引:0,他引:1
R. Travis Belote Steve PrisleyRobert H. Jones Matthew FitzpatrickKirsten de Beurs 《Forest Ecology and Management》2011,261(7):1315-1324
Factors influencing the relationship between ecosystem productivity and biological diversity form the basis of much ecological theory. An understanding of how productivity-diversity relationships are influenced by scale of observation and unique attributes of ecoregions may provide important insights to aid conservation planning for carbon retention and biodiversity. Here we use publically available datasets to investigate patterns of productivity-diversity and explore potential factors influencing these patterns in forests located in five mid-Atlantic and Appalachian states. We used a geographic information system (GIS) to overlay multiple publically available datasets including remotely sensed estimates of productivity from MODIS and tree diversity estimated from the forest inventory analysis (FIA) database. We evaluated productivity-diversity relationships using two scales of observation (among and within ecoregions). We also determined if productivity-diversity relationships might be related to region-wide patterns in land use, and if the relationships varied by forest type, land management zones, and along gradients of mean productivity and diversity. Productivity-diversity relationships depended on scale and varied among ecoregions, and land use was correlated with both productivity and diversity. Mountainous ecoregions were characterized by positive productivity-diversity relationships, whereas coastal ecoregions were characterized by negative productivity-diversity relationships. Forest types and management zones that were on average less productive and more diverse exhibited positive productivity-diversity relationships across stands (the most productive stands were more diverse). In contrast, ecoregions and forest types that were on average more productive and less diverse exhibited negative productivity-diversity relationships (the most productive stands were less diverse). In conclusion, regional and local ecological and anthropogenic factors likely influence productivity-diversity relationships and these relationships appear to change along gradients of productivity and diversity. 相似文献
119.
Tracey D. Tuberville Terry M. Norton Bradley J. Waffa Cris Hagen Travis C. Glenn 《Biological conservation》2011,(1):175-183
Population manipulations such as translocation are becoming increasingly important tools in the management of rare and declining species. Evaluating the effectiveness of such manipulations requires comprehensive monitoring of population processes, including dispersal, survivorship, and reproduction. We investigated the mating system of a translocated population of gopher tortoises (Gopherus polyphemus) established through multiple releases, which occurred primarily during 1987–1994. During 2006–2007, we sampled and genotyped 27 candidate males (candidate sires), 34 candidate females (candidate dams), and 121 offspring from 19 clutches at five polymorphic microsatellite loci to determine the relative frequency of multiple paternity and to estimate individual reproductive success. Multiple paternity was detected in 57% of clutches genotyped, and females of single-sire clutches and females of multiple-sire clutches were of similar size. Reproductive success varied among male tortoises, and successful sires were significantly larger than males to which no offspring were attributed. Among successful sires, previously established males sired a disproportionate number of the offspring sampled, despite being significantly smaller than subsequently released males. The high variance in individual reproductive success and the apparent reproductive advantage associated with prior residence observed in this gopher tortoise population has important implications for the design of future translocation projects. 相似文献
120.
Travis J 《Science (New York, N.Y.)》1993,259(5101):1534-1536